Field of the Invention
The present disclosure relates to a medical imaging apparatus, a program installable in a medical imaging apparatus, and a medical imaging method.
Description of the Related Art
Ischemic heart disease (IHD), which is caused by blocking the blood flow to myocardium due to obstruction or narrowing of coronary arteries, generally occurs in endocardium and progresses toward epicardium. When the disease reaches epicardium, it may be difficult to cure the disease. It is thus significantly necessary to detect the disease in an early stage. To this end, techniques for detecting narrowing of coronary arteries in an early stage by using various medical image diagnostic apparatuses have been sought in recent years.
Japanese Patent Laid-Open No. 2013-10005 discloses a medical imaging apparatus capable of detecting the presence of a narrowing of coronary arteries by obtaining a blood flow rate or the gradient of a blood flow rate in each region of coronary arteries, from a plurality of items of volume data captured at different times, which are obtained by capturing, by an X-ray computed tomographic (CT) scanner, images of the heart of a patient (subject being tested) into which a radiocontrast agent has been injected, and by generating an image that represents the form of the coronary arteries colored in accordance with the level of the blood flow rate or the gradient of the blood flow rate.
However, the medical imaging technique disclosed in Japanese Patent Laid-Open No. 2013-10005 requires to obtain a plurality of items of volume data captured at different times by the CT scanner. Not only the amount of captured data becomes vast, but also the amount of the patient's exposure to radiation becomes great. It is thus hard to say that this is a simple image generating technique.
Research on diagnosis of ischemia in recent years has found that a mechanical stress on myocardium causes an ischemic state to appear in systole. This shows the possibility that using a medical image captured in such systole can contribute to early detection of ischemic heart disease.